Cooling means for electrode tips



Patented Nov. 6, 1945 COOLING MEANS FOR ELECTRODE TIPS Thomas A..Wilson, Stratford, Conn., assignor to United Aircraft Corporation, East Hartford,

Conn., a corporation of Delaware Application July 18, 1944, Serial No. 545,424

12 Claims.

This invention relates to improvements in fluid cooled welding electrodes.

In electrodes used for resistance welding, as for example spot welding, it is necessary to make the tip of the electrode removable, so that a tip having the particular shape best designed for the work may be quickly and easily inserted in the holder. It is further necessary to provide an axial passage in the tip and provide for the circulation of a stream of cooling fluid, usually water, through the holder and to the extremity of the tip passage.

An object of the present invention is to provide improved means for circulating the cooling fluid in such an electrode.

Another and more specific object of the invention is to provide improved means for supporting a cooling tube within such a removable electrode tip in such manner that the tube is properly axially located in the tip passage and is automatically connected with the tip holder cooling tube to establish fluid circulation by the act of inserting the tip in the holder.

A further object of the invention is to circulate the cooling fluid to the extremity of the coolin passage in the electrode tip regardless of variation in length of the tips.

A still further object of the invention is to improve the cooling and prolong the life of electrode tips.

Other objects and advantages will be apparent from the following detailed description of a preferred embodiment thereof considered in connection with the accompanying drawing.

In the drawing,

Fig. 1 is a vertical section through an electrode embodying the invention.

Fig. 2 shows a modified construction for positioning the electrode tip cooling tube.

Fig. 3 is a section on line 3-3 of Fig. 2.

As herein shown the electrode includes a tip face 20. The tip also has a tapered shank portion 22 which is received in a correspondingly tapered socket 24 at the extremity of an axial fluid circulating passage 26 in the holder, thus enabling the tip to be removable while providing good electrical contact between the holder and tip when the latter is in place in the socket. A web 28 in passage 26 of the holder is provided with an axial passage 30 within which cooling tube I6 is disposed and is permanently fixed to the web at 34, as by welding. The tube I6 is connected with any suitable supply of cooling fluid (not shown) and terminates within the socket 24 of the holder.

Means are provided in the electrode tip for conveying the cooling fluid discharged from tube 16 to the bottom wall IQ of the passage l8 and for returning the fluid through the space between the tube [6 and the side wall of the passage 26. These means include cooling tube [4, the inside diameter of which is slightly larger than the out- 15 side diameter of tube I 6, and means for supporting the cooling tube in the electrode tip. The tube I4 is adapted to seat at one end against the closed end wall IQ of the passage I8, but has its end bevelled to enable it to discharge the cooling fluid directly against the bottom wall of the passage while permitting free lateral flow of fluid to the return passage 38 surrounding the tube. The tube projects a substantial distance from the tip passage l8 at its other end so that when the tip is seated in socket 24 of the holder the cooling tubes I6 and M will overlap in telescoping relation.

The means for supporting the cooling tube M in the above described position comprises a plurality of leaf springs 40 which are secured to the tube at 42, as by solder, and which bear at their free ends against tube l4 while intermediate portions 44 thereof bear laterally against the wall of passage l8. These springs are disposed in spaced relation about the periphery of the tube and center the tube in passage 18 while also retaining the tube in the position shown in which the end thereof abuts the bottom wall l9.

As shown in Figs. 2 and 3, two of the springs 4!! are replaced by rigid spacer members 49a which are generally channel shaped members having their backs soldered to tube l4 and having the ends of their legs bearing against the wall of passage 18. This construction is preferred to that shown in Fig. l in some instances since the single spring 4!! in urging the tube i4 and the attached spacer members against the wall of passage [8 very accurately centers the tube I4 relative to the passage l8 and the telescoping tube 15. Preferably the supporting members All and 40a are spaced apart one hundred and twenty degrees as shown in Fig. 3.

In operation, cooling fluid, usually water, is supplied to the electrode through telescoped tubes l6 and 4 to the bottom of passage [8 in the tip, where it is directed against the inner surface l9 of the electrode tip. The fluid then flows back through the space between the axially disposed tubes [4 and I6 and the side Walls of passages l8 and 28, to a suitable outlet connection (not shown) in the holder.

In inserting a new tip in the holder it is only necessary to press the tube l 4 into the tip passage I8 as far as it will go and insert the protruding end of the tube over the end of tube I 6 as the shank 22 is pressed into socket 24 in the holder. Each tip may be provided with a tube M or if desired the tubes may be removed and inserted in the new tip to be placed in the holder.

It will be evident that as a result of these improvements effective cooling of the electrode tipis assured regardless of variations in thelength of the difierent tips inserted in the holder, since the cooling fluid is always discharged from the.

telescoping supply tubes at the extreme end of the tip passage and directly against the closed end thereof, the outer surface of which constitutes the working face of the electrode.

It will also be evident that the construction is extremely simple and free from the dimculties previously encountered with adjustable cooling tubes carried by the electrode holder itself.

While two embodiments of theinvention have been shown in the drawing and described herein, it will be understood that various changes may be made in the construction and arrangement of the parts without departing from the scope of the invention as defined by the following claims.

I claim: 7

1. A welding electrode comprising an openended tubular body, a hollow tip having a closed end and having its open end removably connected to the open end of said body, means for circulating a cooling fluid stream within the body and tip including an axially disposed tube fixed to said body and terminating adjacent the open end thereof and a cooperating axially disposed tube carried by said tip havingone end terminating adjacent the closed end of the tip and having its other end telescoping with the tube-in said body, and means for positioning said tip carried-tube in the aforesaid fluid circulating position relative to said tip during removal and insertion of the latter in said electrode body.

2. A welding electrode comprising an openended tubular body, a hollow tip having a closed end and having its open end removably connected to the open endof said body, means for circulating a cooling fluid stream within the body and tip including an axially disposed tube'flxed to said bodyand terminatingadjacent the open end thereof .and acooperating axially disposed tube carried by said tip having-one end. terminating adjacent the closed end of the tip and having its other end telescoping with the tube in said body, and means between the tip side walls and said tip carried tube for positioning the latter against axial displacement while permitting fluid circulation in the passage therebetween.

3. A welding electrode comprising an openended tubular body, a hollow tip having a closed end and having its open end removably retained in the open end of said body, means for circulating a cooling fluid stream within said bod and tip including an axially disposed tube fixed to said body and terminating adjacent the open end thereof and a cooperating axially disposed tube carried by said tip having one end terminating adjacent the closed end of said tip and having its other end telescoping with the tube in said body, and means including a resilient member disposed in the space between said cooperating tube and the side wall of said tip for centering said tube in said space and positioning the same against axial displacement while permitting fluid circulation in the passage surrounding said telescoped tubes.

4. A welding electrode comprising an openended tubular body, a hollow tip having a closed end and having its open end removably retained in the open end of said body, means for circulating a cooling fluid stream within the body and tip including an axially disposed tube fixed to said body and terminating adjacent the open end thereof and a cooperating axially disposed tube carried by said tip having one end terminating adjacent the closed end of the tip and having its other end telescoping with the tube in said body,

and means including a resilient member fixed to said tip carried tube and disposed in the space between the tube and the side wall of said tip for centering the tube in said space and positioning the same against axial displacement while permitting fluid circulation in said space.

5. A welding electrode comprising an openended tubular body, a hollow tip having a closed end and having its open end removably retained in the open end of said body, means for circulating a cooling fluid stream within the body and tip including an axially disposed tube fixed to said body and terminating adjacent the open end thereof and a cooperating axially disposed tube carried by said tip having one end terminating adjacent the closed end of the tip and having its other end telescoping with the tube in said body, means including a leaf spring fixed to said tube and bearing against the side wall of said tip for centering said tube in the hollow tip and restraining the same against axial displacement.

6. A welding electrode comprising an openended tubular body, a hollow tip having a closed end and having its open end removably retained in the open end of said body, means for circulating a coolin fluid stream within the body and tip including an axiallydisposed tube fixed to said body and terminating adjacent the open end thereof and a cooperating axially disposed tube carried by said tip having one end terminating adjacentthe closed end of said tip and having its other end telescoping-withthe tube in said body, and tube supporting means disposed in the space between said cooperating tube and the side wall of said tip including a plurality of leaf springs fixed to said cooperating tube at spaced points about its periphery and bearing against the adjacent side Wall of'said tip for centering said tube in said space and restraining the same against axial displacement.

'7. A removable tip for welding electrodes comprising a hollow body closed at one end and having a tapered shank at its open end for retaining the same in a tip holder socket, an axial tube for circulating a cooling fluid within said tip having an oblique end seated against the closed end of said tip, and tube positioning means including a spring member disposed in the space.

between said tube and the side wall of said tip for positioning said tube relative to said tip.

8. A removable tip for welding electrodes comprising a body having an axial passage for the circulation of cooling fluid therein, said passage being closed at one end, an axial tube in said 9. A removable tip for welding electrodes comprising a generally cylindrical body having an axial passage for the circulation of cooling fluid therein, said passage being closed at one end of said tip and said body having an external taper at its other end for positioning said tip in the socket of a tip holder, an axial tube in said passage for conveying coolin fluid to the bottom of said tip passage and discharging the same against the closed end thereof, said tube having an outside diameter smaller than the diameter of said passage, and resilient means including a. plurality of leaf springs fixed to said tube and disposed in spaced relation about the periphery of said tube and bearing against the side wall of said passage for positioning said tube in said tip passage.

10. A welding electrode comprising an openended tubular body, a hollow tip having a closed end and having its open end removably retained in the open end of said body, means for circu lating a cooling fluid stream within said body and tip including an axially disposed tube fixed to said body and terminating adjacent the open end thereof and a cooperating axially disposed tube carried by said tip having one end terminating a jacent the closed end of said tip and having its other end telescoping with the tube of said body, and supporting means ,for said cooperatin tube including a plurality of spacing members located in the space between said cooperating tube and the adjacent side wall of said tip' on opposite sides of said cooperating tube, at least one of said spacing members being rigid and at least one being resilient.

11. A welding electrode comprising an openended tubular body, a hollow tip having a closed end and having its open end removably retained in the open end of said body, means for circulating a cooling fluid stream within said body and tip including an axially disposed tube fixed to said body and terminatin adjacent the open end thereof and a cooperating axially disposed tube carried by said tip having one end terminating adjacent the closed end of said tip and having its other end telescoping with the tube of said body, and supporting and centering means for said cooperating tube including a plurality of spacing members secured to said tube in spaced relation about the periphery thereof and bearing against the side wall of said tip, certain of said members being rigid and at least one being resilient.

12. A welding electrode comprising an openended tubular body, a hollow tip having a closed end and having its open end removably retained in the open end of said body, means for circulating a cooling fluid stream Within said body and tip including an axially disposed tube fixed to said body and terminating adjacent the open end thereof and a cooperating axially disposed tube carried by said tip having one end terminating adjacent the closed end of said tip and having its other end telescopin with the tube in said body, and opposed resilient and nonresilient members disposed in the space between. said cooperating tube and the side wall of said tip and on opposite sides of the latter for frictionally positioning said tube against displacement while permitting fluid circulation in the passage surrounding said telescoped tubes.

THOMAS A. WILSON. 

